It is true that those North Koreans that defected have not been crazy, but those defectors are not representatives of the country’s masses.
You cannot discount half a century of communist programming and propaganda. North Korea needs at least 1 full generation of effective quarantine and de-programming. After WWII, Germany and Japan unconditionally surrendered with their leadership either killed off (like Nazis) or neutered (like the Emperor). If North Korea does not go through at least that, there will be bigger problems at hand than the pork chop threatening to launch missiles.